1. Field of the Invention
The present invention relates to a combustion chamber system for an internal engine using a kerosine as a fuel, which has an excellent power performance and a simple structure.
2. Description of the Prior Art
It is generally known in an internal combustion engine that in any kinds of fuel one effective means for increasing a thermal efficiency to improve a specific fuel consumption and a power output is to increase the compression ratio of engine. However, it is also known that a too high compression ratio causes knocking (abnormal combustion) which may rather bring about reduction in power.
Because kerosine has a lower octane value than that of gasoline, a kerosine internal combustion engine tends to cause knocking as compared with a gasoline internal combustion engine and has a compression ratio limited lower. For reasons of inexpensiveness, excellence in economy and ease to deal with, however, it is desired to develop a high power and high performance kerosine engine having an increased compression ratio with an occurrence of knocking suppressed.
Knocking phenomenon is generally said to be caused by a rapid spontaneous ignition of an unburnt end gas i.e., a final part of the mixture to be burned to the flame propagation. Requirements for inhibiting the knocking include:
(1) increasing a flame speed to raise a combustion speed; and
(2) shortening the distance of flame propagation. It is also known that an engine having an auxiliary combustion chamber relatively well meets the above requirements and has an excellent antiknocking property.
However, any conventional engine having an auxiliary combustion chamber is aimed at reducing air pollution by a lean burn method and is unavoidably complicated in structure and costly. There has not yet been put into practical use such a high power kerosine engine having a good specific fuel consumption and having a simple structure wherein a high compression ratio is obtainable and occurrence of knocking is inhibited to a possible extent while a combustion efficiency is enhanced.